Light sensitive cell



l l I I .l

INVENTOR. ,4. CARPENTE'Q E Poss ATTORNEY.

A. CARPENTER ET AL LIGHT SENSITIVE CELL Filed Oct. 9, 1934 May 26, 1936.

Patented May 26 1936 UNITED STATES v nIGn'r SENSITIVE can.

Arthur Carpenter, New York, and Ernest Ross,

Richmond Hill, N. Y., assignois to United Research Corporation. LongIsland City, N. Y., a corporation of Delaware Application October 9,1934, Serial No. 747,610

3 Claims.

The invention relates to a light sensitive cell and mounting thereforand is in the nature of an improvement over the cell'construction shownin the patent to Lyon 1,948,766.

An object of the present invention is to avoid the use of spring contactterminals as shown in the above patent, and incidentally to avoid thefunction of the cap member 9 for retaining the cell in position.

Another object of the invention is to assign to the cap member 9 a newfunction namely, that of serving as the contact terminals, which leadsto making the cap member in two parts.

Another object of the invention is to removably mountthe selenium cellclosely adjacent to a sound The manner in which these objects areaccomplished will be apparent from the following description andaccompanying drawing wherein:

Fig. 1 is an enlarged sectionalelevation view showing a preferred formof my invention.

Fig. 2- is a plan section taken in a plane represented by line 2-2 inFig. 1.

Fig. 3 is a perspective view of my invention. I

Fig. 4 is an enlargedview taken along the line H of Fig. 1 and showingthe interdigitated electrodes.

Fig.5 is an elevational view, partly in section, showing the inventionin a suitable holder and in connection with a sound'reproducingapparatus.

Fig. 6 is a plan section taken in a plane repre 'sented by line 66 ofFig. 5. More particularly describing the invention. the light sensitivecell l which is approximately '1;

of an inch high. ,8 inch wide, and inch thick,

parent base'plate 5 such as glass, on the rear- 45 side of which isplated or fused a coating of hard metal 6. generally an alloy ofplatinum or palladium for example as in the patent to Carpenter No.1-,940245. Over the metal Sis plated another coatirg I of a softer metalsuchas silver so as 50 to provide a base on which wires 8 and 9 may besoldered. After the layer of metals 6 and I has been deposited on thesurface of the glass plate 5, it is separated into two electrodes l0 andII by tracing a sinuous path ll thereon to form a series ofinterdigitated projections l2 and I3 retainers to hold the assembly inpla as will be seen in Fig. 4. This trace may have rounded corners as inthe patent to Carpenter No. 1,942,958. A thin layer of selenium H orother light sensitive material is then deposited on the face of themetal. I to bridge the gap 5 formed between the two electrodes It andi8. This is usually accomplished by sublimation, that is, by vaporimngthe light sensitive material from asolid and allowing it to condenseupon the surface of the metal I. 10

A cup-shaped piece of glass Isis attached to the rear surface of themetal layer 1 and covers the selenium ll. In order to provide a securevbond therebetween, I provide an annular groove IB formed in the outersurface H of the cup l5 to receive cement material l8. .The groove l6thereby provides for a large area of adhesion to securely hold the cupin position on the surface l1.

Light sensitive cells of this type are consider- 20 ably affected by thepresence of moisture and for this reason I apply a coating of moistureproof material I! such as asphalt to' the entire surface of theelectrode assembly 4 except for a portion 20 atthe front of the glassplate 5 to allow light to be transmitted to the interior of the cell.

A recess 2| is formed in the base 2 to allow the cup member l5 to bereceived therein. Also, a 30 pair of vertically disposed grooves .22 and23 are formedlin the top and bottom of the base member 2 to receive the'wires 8 and 9.

The upper and lower portion of outer surface ofthe base 2 are alsorecessed as at 24 and 25 to receive metal .caps 26 and 21 which havesoldered thereto the wires 8 and 9 as shown at 28 and 29 respectively.It will be seen therefore that the caps 26 and 21' serve to form contactterminals for the electrodes l0 and ID" as well as to form In order tohold the caps 26 and 21 in position.

I provide detents (not shown) in the base 2 wherein the sides of thecaps are indented as at l 'land 3| inFig. 3.

The cell may be assembled as follows: The lead in wires 8 and 9 aresoldered to their respectiveelectrodes ll and II, the wires land 9 atthis time being substantially longer than as shown in Fig. 1. Theelectrode assembly 4 is then placed intherecess3,and thecaps26and2'larefltted into the position shown in Fig. 1, after threading thewires 8 and 9 through the apertures 22' and 29' in the caps 2S and 21respectively. The caps 2i and 21 are then fastened in position byindenting the same as at and 3| in Fig. 3 into indentations, not shown,in the base 2, similar indentations, not shown, also being provided inthe opposite side of the cell. The wires 8 and 9 are now pulled to bringthe electrode assembly 4 in contact with the bottom of the recess 3 asshown in Fig. 1 and the wires 8 and 9 are soldered to the caps 26 and 21respectively as shown at 28 and 29, and the surplus portion of thesewires 8 and 9 which extends beyond the caps is removed.

It, will be seen from the above description that the invention is of theutmost simplicity and may be constructed economically in productionquantities.

Figs. 5 and 6 show a cell I mounted in a" holder provided in a soundreproducing unit such as a talkie" picture projector wherein the filmguides or light blocks 32 and 33, mounted on a vertical wall section 34,guide the film 33', having a sound track thereon, past an aperture orlight passage 35 formed in the film guides 32 and 33. The aperture 35 isadapted to receive a ray of light from a light source of constantintensity (not shown) which is projected through a suitable opticalsystem partly shown at 36 onto the sound track of the film 33. A recess38 is formed in the rear of the film guide 32 opposite the lightaperture 35 and is lined with strips of insulation 39, 40, and 4|. Thestrip 40 has an aperture 35' which registers in alignment with theaperture 35. To the rear of the recess 38 is mounted a contact block 42preferably formed of bakelite or other suitable insulating material. Theblock 42 is shown as being mounted on the wall 34 by means of a capscrew 43 and has a ledge 44 extending into the rear of the recess 38 toinsulate the cell i from the wall 34 and also to position the cell sothat the light aperture 35 will register in alignment with the centralportion of the cell which contains the interdigitated electrodes l0 andIII. A pair of contact pins 45 and 4B are placed in counterbored holes41 and 48 provided in the block 42. Springs 49 and 50 are mounted in theenlarged counterbores of the holes 41 and 48 and abut against theshoulders 5| and 52. The other ends of the springs 49 and 5D engageenlarged heads 53 and 54 of the pins 45 and 46 respectively. Wires 55and 56 connect the contact pins 45 and 46 with a suitable soundamplifying system not shown.

As will be seen in Fig. 6, the cell I projects out a short distance fromthe guide 32 and the block 42 to permit grasping the projecting cellportion to allow for easy and quick insertion and withdrawal of thecell.

As shown in Figs. 1 and 3, the base 2 and the caps 26 and 21 areprovidedwith shoulders or projections 51 and 58 whereby each end of thecell I is supported along a. line insteadof. by an extended surface, inthe recess 38 of the light block 32. This facilitates sliding the cell linto and out of the recess 38.

The spring pressed terminals or pins 45 and 46 constitute means forresiliently holding the cell I against the vertical wall of the recess38 and in close proximity to the film 33', for sound reproductionpurposes.

Having thus described the invention, what is claimed as new and desiredto secure by Letters Patent, is:

I claim:

l. A light sensitive cell comprising a transparent plate, electrodes onsaid plate, light sensitive material bridging said electrodes, a base ofinsulating material having a recess adapted to receive said transparentplate, a pair of contact terminals on said base, each of said terminalscomprising a metallic shell closely fitting an end of said base andoverlying said recess, a plurality of apertures in said base, and aconductor in each of said apertures, each of said conductors beingintegrally united at one end to one of said electrodes, and at the otherend to one of said terminals.

2. A light sensitive cell comprising a transparent plate, electrodes onsaid plate, light sensitive material bridging said electrodes, a base ofinsulating material having a recess adapted to receive said transparentplate, a pair of contact terminals on said base, each of said terminalscomprising a metallic shell closely fitting an end of said base andoverlying said recess, and lead ing-in conductors fastened to saidelectrodes and to said terminals respectively for retaining said plateagainst the bottom of said recess.

3. A light sensitive cell comprising a transparent plate, electrodes onsaid plate, light sensitive material bridging said electrodes, a capsealing said electrodes, a base of insulating material having a recessadapted to receive said transparent plate and said cap, a pair ofcontact terminals on said base, each of said terminals comprising ametallic shell closely fitting an end of said base and overlying saidrecess, a plurality of apertures in said base, and a conductor in eachofsaid apertures, each of said conductors being integrally united at oneend to one of said elec trodes, and at the other end to one of saidterminals, each of'said terminals extending over said plate.

ARTHUR CARPENTER.

ERNEST ROSS.

